Issue(s)
- Getting an Alarm 14 "Spindle at Speed timeout, clear before continuing"
- pwn CNC won't run or start
Resolution(s)
- Test the Pwn CNC spindle works in manual mode
- Confirm the wiring is correct
- Ensure EEPROM settings are correct
- Ensure the VFD settings are correct
PwnCNC VFD Wiring to SuperLongBoard
pwnCNC connection using either the Modbus or the RS485 Jack on the controller.

PwnCNC Firmware / gSender Settings
$16 = all off
$30 = 24000
$31=6000 Minimum RPMs
$340 = 0
$374 = 19200
$375 = 50
$392 = 6
$395=MODVFD
$462=40960
$463=40961
$464=36864
$465=1
$466=2
$467=6
$468=25
$476 = 1
- If $476 is not available, a neighbouring grbl command of $478 spindle address






There are two variations of SLB, the SLB and the SLB-EXT
You'll know which one you have by the presence or absence of the relay highlighted below. The SLB-EXT has the relay.
If you have the SLB, $340 = 0
If you have the SLB-EXT, $340 = 5
(A customer's method: resetting firmware defaults to AltMill 4x4 + Spindle then importing settings from this PwnCNC article: https://support.pwncnc.com/kb/article/468-super-long-board/)
PwnCNC VFD Settings
Then adjust your VFD Parameters. To navigate the system, hit the mode button (p0.0.00 should be blinking) using the up and down arrows, and double right arrow, and enter then mode to exit)
Auto Control
P0.0.03 = 2
P0.0.04 = 9
P4.1.00 = 04
p4.1.01 = 4
Manual Control
P0.0.03 = 0
P0.0.04 = 2
P4.1.00 = 3
p4.1.01 = 0